Fire-rated grid for a suspended tile ceiling and runners therefor

ABSTRACT

A grid for a suspended tile ceiling in the main runner of which the web section is formed with a laterally offset flange at one edge and a tubular bead at the opposed edge, and with a plurality of spaced slots for receiving the ends of cross runners. The main runner has a longitudinally extending slit formed therein below each slot in proximity to the lower edge of the runner, and longitudinally extending slits formed in opposed wall portions of the bead above each slot. The cross runners of the grid may have similar longitudinally extending slits formed in the web and bead at a midpoint thereof.

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United States Patent ORNAMENTED MliRRORS AND METHOD OF MAKHNG SAME Jonathan Turner, Chicago, 111., assignor to Turner Manufacturing Company, Chicago, 11]., a corporation of Illinois Application September 18, 1953, Serial No. 381,022

2 Claims. (Cl. 41-22) This invention relates to the production of ornamented or decorated mirrors, and particularly to the production of mirrors having ornamented or decorated portions or areas of simulated engraved, etched or cut character.

It is an object of the present invention to produce ornamented mirrors of the foregoing class in a novel manner or sequence of steps and by a novel arrangement of parts or components, to result not only in an enhanced decorative effect, but also in great economies over the prior process of engraving or grinding and polishing to produce highly reflective designs in relief in the mirror.

The character of the product of the present invention and the method of producing the same will be further understood and explained in connection with the following specification and drawings, wherein:

Fig. 1 is a plan view illustrating a piece of clear glass of which the mirror of my invention is to be formed, having aplanar temporary design mask thereon.

Fig. 2 is a view similar to that of Fig. 1, illustrating a succeeding mirroring step.

Figs. 3 and 4 illustrate further successive steps in the process, wherein the temporary design mask is respectively partially and completely removed.

Fig. 5 is a plan view of an embossed backing sheet for assembly with the mirrored piece illustrated in Fig. 4.

Fig. 6 is an enlarged sectional view of the components shown in Figs. 4 and 5 spaced apart to illustrate their relationship to each other prior to being brought together.

Fig. 7 is a plan view of the face of the assembled decorated mirror.

Referring to the drawings, the reference numeral 10 indicates a plate of glass of which the mirror is to be formed for the purpose of illustration, it being understood that the mirror may be of any size or shape, and that the ornamentation may be of any portion thereof, such as the border, or that mirrored panels may be formed in accordance with the present invention for assembly with non-ornamented mirrors or panels, and the like. The

ornamental designs shown in the drawings are likewise for the purpose of illustration only.

As a first step in the process of forming the mirror of the present invention, I apply to one surface of the clear glass, which is to be the back of the mirror, a solid adherent mask 11 having the outline of the desired ornamentation, and which is impervious to the conventional mirror silvering solution to be subsequently applied thereover, and which adheres firmly to the glass so that none of the silvering solution will seep under the edges to mar the desired sharp fidelity of design outline. This design mask is applied by conventional silk screen means, and for this purpose I employ a solvent solution of a strippable film-forming plastic which after application flows to close any openings left by the meshes of the silk screen and Patented Sept. 24, 1957 air-dries to a solid impervious film adherent to the applied glass, but which can subsequently be lifted therefrom as a unit with ease. For the purpose of illustration, a suitable material may be a strip lacquer" such as one composed of vinyl chloride-acetate copolymers plasticized with phthalate type plasticizer and dissolved in suitable organic solvents, and having a viscosity of from about to about 78 Ku at g.

After this liquid plastic design is silk-screened onto the glass and air or otherwise dried, the side of the glass to which it was applied is then subjected to silvering by a conventional mirror silvering process, for example with a conventional aqueous silver-nitrate-reducing agent mirror silvering solution to deposit a silver coating 12 as in Fig. 2. After the silver becomes firmly fixed to the glass and dried, the plastic mask 11 is stripped from the glass as shown in Fig. 3 to leave a clear design area 13 as shown in Fig. 4 surrounded by the silvered area 12.

A separate opaque sheet of silver-coated thermoplastic material 14, such as for example cellulose acetate, suit ably surface silvered by the vacuum process, is then heat embossed with a design 15 complementary to the outline 13 left by stripping the plastic mask 11, to provide intermediate detail. The embossed silvered sheet 14 is then placed against the silvered back 12 of the mirror in matching relationship so that the embossed design 15 is visible through the clear area 13 of the mirror as shown in Fig. 7, to provide a novel simulated engraved effect, and the two suitably secured together and backed up or formed in any suitable manner.

I claim as my invention:

1. A decorative mirror comprising a glass panel having a silvered reflective coating on one planar face thereof and formed with clear unsilvered areas defining a design outline, and an opaque silvered reflective backing sheet of relatively thin thermoplastic material secured against said coated glass face having an embossed design therein disposed rearwardly of said face complementary to and visible through said clear unsilvered glass areas within the confines of said design outline thereof.

2. The method of forming decorative mirrors which comprises, applying to one face of a glass plate a solvent solution of an adherent, strippable plastic to mask an area thereof having the outline of a desired decorative design, drying said plastic material to a solid film, applying over the whole of said partially masked face an aqueous mirror silvering solution, drying said solution, stripping said plastic therefrom to leave a clear unsilvered area defined by said design outline, embossing a reflective silvered sheet of thermoplastic material with a design complementaryto the outlines of said unsilvered glass area and securing it against said silvered glass surface.

References Cited in the file of this patent UNITED STATES PATENTS 125,726 Davis Apr. 16, 1872 494,255 De Jong Mar. 28, 1893 718,281 Rountree Ian. 13, 1903 861,822 Feher July 30, 1907 1,342,767 Schlesinger June 8, 1920 2,065,406 Silverman Dec. 22, 1936 2,141,488 Riedel Dec. 27, 1938 2,157,649 Birdseye et al Mar. 21, 1939 2,181,926 Tiger Dec. 5, 1939 2,456,376 Chirelstein Dec. 14, 1948 2,657,150 Hermanson Oct. 27, 1953 

1. In a grid for a suspended tile ceiling, said grid including main runners and transverse runners supported on said main runners, said runners each comprising an upright web section having a laterally offset flange at its lower edge and a tubular reinforcing bead at its upper edge, each said transverse runner having a lock tongue at the end of its web of a reduced height relative to its connected web; each said main runner of said grid having a plurality of spaced, transversely extending slots formed in the web thereof, with each slot terminating short of said flange and said bead and adapted to receive therein the lock tongues of transverse runners inserted thereinto from opposed sides of the web thereof; each said main runner having a plurality of spaced, longitudinally disposed heat stressrelieving slits formed in the web thereof in close proximity to the lower edge of said web, with one of said slits being positioned in line with each transversely extending slot in the web of said main runner, each of said slits having opposed edges along the length thereof which are disposed against each other.
 2. The grid of claim 1, wherein each said transverse runner has a slit formed therein at a midpoint of the web thereof, adjacent its bottom edge.
 3. The grid of claim 2, wherein each said slit in said reinforcing bead extends through opposed wall portions thereof, substantially in vertical register with a slit in the web thereof.
 4. The grid of claim 1, wherein each said main runner has a plurality of spaced, longitudinally extending heat stress-relieving slits formed in the wall of the reinforcing bead thereof, each of said slits having opposed edges along the length thereof which are disposed against each other.
 5. The grid of claim 4, wherein said slits in said bead are formed in opposed wall portions of said bead.
 6. The grid of claim 4, wherein said slits in said reinforcing bead are each formed in vertical register with one said slit formed in said web thereof.
 7. The grid of claim 1, wherein said slits are regularly spaced from one another.
 8. The grid of claim 7, wherein each said slit is spaced from the lower edge of said web and is formed with a downwardly offset V-shaped section at its center, said offset V-shaped section having its apex at substantially the lower edge of said web.
 9. The grid of claim 8, wherein each said slit is formed with a downwardly extending portion at each end thereof; the lower ends of said downwardly exTending portions terminating at substantially the lower edge of said web.
 10. The grid of claim 7, wherein said slits are each formed below one of said slots.
 11. The grid of claim 10, wherein said slits are each centered on the slot above it and extend to each side thereof.
 12. A main runner for a grid for a suspended tile ceiling, comprising an upright web section having a laterally offset ledge at its lower edge and a tubular reinforcing bead at its upper edge, and a plurality of spaced, transversely extending slots formed in the web thereof, with each slot terminating short of said flange and said bead and adapted to receive therein the lock tongues of transverse runners, said main runner having a plurality of spaced, longitudinally extending heat stress relieving slits formed in the web thereof, parallel to said lower edge and in close proximity thereto, with one of said slits being positioned in line with each transversely extending slot in the web of said main runner, each of said slits having opposed edges along the length thereof which are disposed against each other.
 13. The runner of claim 12, wherein slits are regularly spaced from one another.
 14. The main runner of claim 12, wherein said slits are each formed below each one of said slots and extends to each side thereof.
 15. The runner of claim 14, wherein each said slit is spaced from the lower edge of said web and is formed with a downwardly extending V-shaped section at its center, said V-shaped section having its apex at substantially the lower edge of said web.
 16. The grid of claim 12, wherein said main runner has a longitudinally extending heat stress-relieving slit formed in the wall of the bead thereof, each of said slits having opposed edges along the length thereof which are disposed against each other.
 17. The grid of claim 16, wherein said slits in said web portion and said bead are centered on said slots.
 18. The grid of claim 16, wherein said slits in said bead are formed in opposed wall portions thereof. 